Munitions Response Initiatives

A munitions response project starts with a review of the site historical records. This leads to construction of a Conceptual Site Model (CSM), which includes all known or suspected areas of munitions use, such as storage bunkers, firing points, target circles and aim points. In rare cases, this initial CSM is sufficient, but most often the historical records are incomplete and significant uncertainties remain about munitions use at the site. In these cases, a technique termed wide area assessment (WAA) may be employed. WAA involves the use of reconnaissance technologies to delineate the site into areas of concentrated munitions use and those areas with no evidence of munitions use. WAA also can provide information on the extent, nature, and density of the contaminated areas that facilitates planning for remediation activities.

When site conditions allow, remediation activities on a site follow a standard procedure, termed digital geophysical mapping. The site is systematically surveyed with a geophysical sensor system that has an integrated positioning system, often GPS. Both the geophysical sensor readings and their associated positions are recorded digitally. These data are later used to construct a response map from which areas of anomalous response, or anomalies, can be identified. The locations of these anomalies are tabulated as a list of potential buried UXO, known as a target list. In order for stakeholders to have confidence that this list is complete, a series of quality control measures are undertaken to ensure that the sensor system is working properly and that reasonable detection goals have been established.

In a traditional remedial action, the locations of all anomalies are investigated by digging. Often, fewer than 1% of the detections are actual UXO. Thus, this method expends a huge amount of site resources digging up items that turn out not to be hazardous. Classification uses properties of the anomalies to classify their sources as either hazardous or not. In its most successful form, this classification is based on target parameters derived from fitting physics-based models to the observed sensor responses. Classification using advanced electromagnetic induction sensors has been shown to significantly reduce the cost of a munitions response.

Most munitions response work to date has been on sites on land. Munitions are also found in the underwater environment. Unlike on the land, the risks from munitions in the underwater environment are driven by two very different effects: the explosive hazard associated with encounter and the environmental hazard associated with the release of the constituents contained in the round. Developing understanding and tools to assess the locations of munitions and the potential sources, transport, fate, and effects of munitions constituents in the marine environment is essential to a more complete assessment of the potential for environmental impacts and exposure at current and former military ranges and disposal sites.

SERDP and ESTCP are sponsoring projects seeking to enhance the munitions response process on land and to develop the science to support the management of underwater sites. Some highlights of these research efforts include: